Continuity mistake: In the scene where Dewey and Ms. Mullins are in the bar, the shots from behind Ms. Mullins sitting down show that her left hand is on the table. However, the shots showing the front of Ms. Mullins show her arms folded.
School of Rock (2003)
Plot summary
Directed by: Richard Linklater
Starring: Jack Black, Joan Cusack, Mike White, Adam Pascal
Dewey is going to be evicted from his apartment by his roommate (a substitute teacher) if he doesn't come up with some money. He gets a call from a school principal and pretends to be his roommate and teaches the fifth grade kids how to play rock so he can win the Battle of the Bands and get $2000.
Keylime
More mistakes in School of Rock
Dewey Finn: God of Rock, thank you for this chance to kick ass. We are your humble servants. Please give us the power to blow people's minds with our high voltage rock. In your name we pray. Amen.
Trivia: Miranda Cosgrove, who plays Summer Hathaway, actually has a good voice and plays guitar. She had to take a 45-minute class to learn how to sing badly for the scene where she sang "Memories."
More questions & answers from School of Rock
Answer: It is never said but If I was to guess, they got it from the guy he was pretending to be (Ned's) information from the school office.